Plotter



(No Model.)

. L. I'. RONDINELLA.

PLOTTER.-

No. 434,073. Patented Aug. 12, 1890.

UNITED STATES PATENT OFFICE.

LINO F. RONDINELLA, OF PHILADELPHIA, PENNSYLVANIA.

PLOTTER.

SPECIFICATION forming part of Letters Patent No. 434,073, dated August12, 1890.

Application tiled April 24, 1890.

To all whom it may concern.:

Be it known that I, LINo F. RONDINELLA, a citizen of the United States,and a resident of the city and county of Philadelphia, and State ofPennsylvania, have invented a new and useful Improvement inDrawing-Instruments, of which the following is a true and exactdescription, due reference being had to the accompanying drawings, whichform a part of this application, and in which similar letters denotesimi-lar parts.

My invention relates to that class ot' drawing-instruments which areused in connection with the T-square or straight-edge in meehanicaldrawing` for the purpose of plotting and measuring angles.

The object of my invention is the production of a single instrument,which, when used in connection with the ordinary T-square orstraight-edge, will enable a draftsman to plot and measure any or allangles that are multiples of the angles of thirty and forty-fivedegrees. In the triangles which are now generally used for this purposeit is necessary, in order to obtain all the angles which are multiplesof thirty and forty-tive degrees, that two dierent instruments shall beused, which is a source of annoyance and expense; and my invention isvery advantageous in that all angles multiples of thirty or forty-tivedegrees can be plotted without working in shadowthat is, when thedraftsman faces the light (which is .the ordinary method) any angle amultiple of thirty or forty-tive degrees can be plotted without havingthe edge along which the line is drawn facing the draftsman.

My invention consists of a plain quadrilateral piece of wood or othersuitable Inaterial, the sides of which are at. such angles with eachother that whrn used with the T-soluare or straight-edge the draftsmancan readily lay out or measure any angle which is a multiple of thirtyor of forty-five degrees.

In the drawings, Figures l, 2, and 3 repre- Serial No. 349,226. (Nomodel.)

sent my improved drawing-instrument placed in connection with astraight-edge, the position of the instrument with regard to thestraight-edge being varied in the three figures.

E F, F G, G H, and H E represent the four sides of my improveddrawing-instrument, the sides H E and E F forming a right angle or anangle of ninety degrees, the sides E F and F G forming an angle offorty-five degrees, the sides F G and G H forming an angle of onehundred and sixty-five degrees, and the sides G H and H E forming anangle of sixty degrees.

S represents a portion of an ordinary T- square or straight-edge. Asshown in Figs.

1, 2, and 3, and as is self-evident, the line H E ih Fig. l, the line FG in Fig. 2, and the line G H in Fig. 3, are common to both thedrawing-instrument and the straight-edge. As may be readily seen, byvarying the position of the various sides with reference to thestraightedge, any angle which is 'a multiple of thirty or of forty-fivedegrees can be easily drawn, or if drawn can be easilymeasured.

Having now fully described my invention,

what I claimand desire to p rotect by Letters Patent, is-

An improved drawing-instrument for plotting and measuring angles, whichconsists of a plain quadrilateral piece of wood or other suitablematerial, the sides of which form the angles of ninety degrees,forty-live degrees, one hundred and sixty-tive degrees, and sixtydegrees, respectively, the angles of forty-five degrees and sixtydegrees being adjacent to the right angle, While the angle of onehuudred and sixty-five degrees is opposite to the right angle.

In testimony of which invention I have hereunto set my hand,atPhiladelphia, Pennsylvania, this 23d day of April, 1889.

LINO F. RONDINELLA.

Witnesses:

A. B. ENTWIsTLE, WM. F. GRAY.

